JP2013199854A - Drive control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drive control device for vehicles which facilitates to satisfy an acceleration request of a driver at the time of re-acceleration, in the vehicle including an engine with a supercharger.SOLUTION: When an engine 10 is in a supercharging state, an electronic control unit 52 lowers supercharging pressure Pcm by operation of a waste gate valve 68, as an accelerator pedal opening PAP is smaller. The electronic control unit 52 reduces a supercharging pressure lowering rate ΔPcm, as the accelerator return amount dPAP (accelerator return rate) within a predetermined time TIME01 is larger. Possibility that a driver intends to drive with emphasizing acceleration performance is higher as reduction of an accelerator pedal opening PAP is more rapid, so that it seems high possibility that the driver performs acceleration operation of repressing down an accelerator pedal 88, or the like. Therefore, it is easy to obtain the sufficient supercharging pressure Pcm at the time of re-acceleration after the reduction of the accelerator pedal opening PAP, and there is an advantage that it is easy to satisfy an acceleration request of the driver at the time of the re-acceleration.

Description

  The present invention relates to a technique for improving drivability in a vehicle including an engine having a supercharger.

  2. Description of the Related Art Conventionally, a vehicle drive control device used in a vehicle including an engine having a supercharger is well known. For example, this is the vehicle control apparatus disclosed in Patent Document 1. The control device of Patent Document 1 suppresses the increase in supercharging pressure when the accelerator opening decreases rapidly, and suppresses the occurrence of surging.

Japanese Patent Laid-Open No. 10-077786 JP 2006-152894 A

  By the way, when the driver suddenly decreases the accelerator opening from the state where the accelerator pedal is depressed, it is highly likely that the driver tends to drive with an emphasis on acceleration performance. There is a high possibility that the accelerator pedal will be depressed immediately after the decrease. This is because if the driver intends to decelerate the vehicle, it is considered that the accelerator pedal is gently returned. If supercharging pressure is controlled as in the control device of Patent Document 1 under a situation where there is a high possibility of emphasizing acceleration performance, it is caused by a delay in the boosting pressure when the accelerator pedal is depressed again, that is, when the vehicle is reaccelerated. As a result, the engine torque is insufficient and the driver's acceleration request may not be met. Such a problem is not yet known.

  The present invention has been made in the background of the above circumstances, and the object of the present invention is for a vehicle equipped with an engine having a supercharger, which is easy to satisfy the driver's acceleration request at the time of reacceleration. To provide a drive control device.

  The subject matter of the first invention for achieving the above object is (a) a vehicle including an engine having a supercharger and a supercharging pressure adjusting device for adjusting a supercharging pressure by the supercharger. A vehicle drive control device that lowers the boost pressure by the boost pressure adjusting device as the accelerator opening is smaller, and (b) the lowering rate of the boost pressure as the accelerator return speed for decreasing the accelerator opening is larger. It is characterized by making small.

  The more rapidly the accelerator opening decreases, the more likely the driver is to drive with an emphasis on acceleration performance, and the driver is more likely to perform acceleration operations such as depressing the accelerator pedal again. Therefore, according to the first aspect of the invention, it is easy to obtain a sufficient boost pressure at the time of reacceleration after the accelerator opening is reduced, and it is easy to satisfy the driver's acceleration request at the time of the reacceleration. There are advantages.

  Here, the gist of the second invention is the vehicle drive control device of the first invention, wherein the lowering of the supercharging pressure decreases as the accelerator return speed increases. Is greater than a predetermined first determination value, the supercharging when lowering the supercharging pressure by a predetermined supercharging pressure difference than when the accelerator return speed is equal to or lower than the first determination value. It is characterized by reducing the rate of pressure decrease. In this way, by comparing the accelerator return speed with the first determination value, it is possible to easily determine whether or not to decrease the supercharging pressure decreasing speed.

  The gist of the third invention is the vehicle drive control device of the second invention, wherein (a) the vehicle includes an automatic transmission that outputs the power of the engine to drive wheels. (B) When the accelerator return speed is larger than a predetermined second determination value larger than the first determination value, upshifting of the automatic transmission is prohibited. In this way, it is possible to prevent downshifting at the time of reacceleration after a decrease in the accelerator opening, so that the automatic transmission is frequently shifted as the accelerator opening is temporarily increased or decreased. It is possible to avoid it.

  Here, preferably, the supercharger is an exhaust turbine supercharger that is rotationally driven by the exhaust of the engine and boosts the intake air of the engine.

  Preferably, the larger the accelerator return speed is, the smaller the decrease rate of the boost pressure is such that when the accelerator return speed is greater than a predetermined first determination value, the accelerator return speed is Compared with the case where it is below the first judgment value and under the condition that the difference in supercharging pressure at which the supercharging pressure decreases is equal, the reduction rate of the supercharging pressure is made small.

  Preferably, the higher the accelerator return speed is, the lower the supercharging pressure lowering speed, and the prohibition of upshifting of the automatic transmission are that the accelerator pedal that was depressed during the acceleration of the vehicle returns. Implemented when operated.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a skeleton diagram for explaining a configuration of a vehicle drive device provided in a vehicle to which the present invention is preferably applied. FIG. 2 is an operation table for explaining an operation state of an engagement element when a plurality of shift stages (gear stages) are established in the automatic transmission included in the vehicle drive device of FIG. 1. FIG. 2 is a diagram illustrating signals input to an electronic control device for controlling the vehicle drive device of FIG. 1 and a functional block diagram for explaining a main part of a control function provided in the electronic control device. It is. FIG. 4 is a flowchart for explaining a main part of a control operation of the electronic control device of FIG. 3, that is, a control operation when an accelerator pedal that has been depressed during vehicle acceleration is returned.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a skeleton diagram for explaining the configuration of a vehicle drive device 7 provided in a vehicle 6 to which the present invention is preferably applied. The vehicle 6 includes a vehicle drive device 7 and a pair of drive wheels 38, and the vehicle drive device 7 includes a vehicle power transmission device 8 (hereinafter referred to as “power transmission device 8”) and an engine 10. ing. The power transmission device 8 is interposed between the engine 10 and the drive wheel 38, and is connected to the automatic transmission 12 and the output shaft 13 of the engine 10 between the engine 10 and the automatic transmission 12. And a torque converter 14 interposed therebetween. And the power transmission device 8 is used suitably for FF vehicle mounted in the left-right direction (horizontal placement) of the vehicle 6 (refer FIG. 3).

  The automatic transmission 12 constitutes a part of a power transmission path from the engine 10 to the drive wheels 38 (see FIG. 3), and outputs the power of the engine 10 toward the drive wheels 38. That is, the power of the engine 10 input to the transmission input shaft 26 is output from the output gear 28 to the drive wheels 38. The automatic transmission 12 includes a plurality of planetary gear devices 16, 20, 22 and a plurality of hydraulic friction engagement devices (clutch C, brake B), specifically five hydraulic friction engagement devices (first clutch C1). , Second clutch C2, first brake B1, second brake B2, third brake B3), and one-way clutch F1, and a plurality of speed changes by changing one of the plurality of hydraulic friction engagement devices. It is a stepped transmission in which a stage (gear stage) is alternatively established. For example, the automatic transmission 12 performs a shift according to a preset relationship (shift diagram) based on a vehicle state represented by a vehicle speed V and an accelerator pedal opening PAP (unit:%, for example). In short, it is a stepped transmission that performs a so-called clutch-to-clutch shift that is often used in general vehicles. That is, the shift (downshift or upshift) of the automatic transmission 12 engages and engages with an engagement-side engagement device that is an engagement device engaged for the shift, and is released for the shift. The release-side engagement device, which is the engagement device to be operated, proceeds by releasing operation. Specifically, the first planetary gear device 16 of the automatic transmission 12 is a single pinion type, and includes a first sun gear S1, a first pinion gear P1, a first carrier CA1, and a first ring gear R1. The second planetary gear unit 20 is a double pinion type, and includes a second sun gear S2, a second pinion gear P2, a third pinion gear P3, a second carrier CA2, and a second ring gear R2. The third planetary gear unit 22 is a single pinion type, and includes a third sun gear S3, a third pinion gear P3, a third carrier CA3, and a third ring gear R3. In the second planetary gear device 20 and the third planetary gear device 22, the second and third ring gears R2 and R3 are formed of a common member, and the third pinion gear P3 of the third planetary gear device 22 is the first. It is a Ravigneaux type planetary gear train that also serves as one pinion gear of the two planetary gear device 20. As can be seen from FIG. 1, the transmission input shaft 26 that is an input rotation member of the automatic transmission 12 is a turbine shaft of the torque converter 14. The output gear 28 that is an output rotating member of the automatic transmission 12 functions as a differential drive gear that meshes with a differential driven gear (large-diameter gear) 34 of the differential gear device 32 (see FIG. 3). The output of the engine 10 is transmitted to a pair of drive wheels (front wheels) 38 via the torque converter 14, the automatic transmission 12, the differential gear device 32, and a pair of axles 36 (see FIG. 3). ). The automatic transmission 12 is substantially symmetrical with respect to the center line, and the lower half of the center line is omitted in FIG.

  FIG. 2 is an operation table for explaining an operation state of the engagement element when a plurality of shift stages (gear stages) is established in the automatic transmission 12. The operation table of FIG. 2 summarizes the relationship between the above-mentioned shift speeds and the operation states of the clutches C1, C2 and the brakes B1 to B3, where “◯” indicates engagement and “◎” indicates only during engine braking. In this case, “Δ” represents engagement only during driving. As shown in FIG. 2, the automatic transmission 12 has a first gear stage “1st” to a sixth gear stage “6th” according to the operating state of each engagement element (clutch C1, C2, brake B1 to B3). Are established, and the reverse shift stage “R” is established. Since the one-way clutch F1 is provided in parallel to the brake B2 that establishes the first shift stage “1st”, it is not always necessary to engage the brake B2 when starting (acceleration). The transmission ratio γat of the automatic transmission 12 is determined based on the input rotational speed Nin, which is the rotational speed Nin of the transmission input shaft 26, and the output rotational speed Nout, which is the rotational speed Nout of the output gear 28. It is calculated from the equation “input rotation speed Nin / output rotation speed Nout”.

  The clutches C1 and C2 and the brakes B1 to B3 (hereinafter simply referred to as clutches C and brakes B unless otherwise distinguished) are hydraulic friction engagement devices that are controlled by hydraulic actuators such as multi-plate clutches and brakes. The engagement / release state is switched by the excitation, de-excitation, and current control of the linear solenoid valve provided in the hydraulic control circuit 40 (see FIG. 1), and the transient hydraulic pressure at the engagement / release is controlled. Is done.

  The torque converter 14 includes a pump impeller 14a connected to the output shaft (crankshaft) 13 of the engine 10, a turbine impeller 14b connected to the transmission input shaft 26 of the automatic transmission 12, and a one-way clutch. And a stator impeller 14c connected to a housing (transmission case) 30 of the automatic transmission 12, and a fluid transmission device that transmits the power generated by the engine 10 to the automatic transmission 12 via a fluid. is there. Further, a lockup clutch 46, which is a direct coupling clutch, is provided between the pump impeller 14a and the turbine impeller 14b so as to be engaged, slipped, or released by hydraulic control or the like. It has become. Strictly speaking, when the lockup clutch 46 is engaged, the pump impeller 14a and the turbine impeller 14b are integrally rotated by being fully engaged.

  The engine 10 is an internal combustion engine such as a diesel engine or a gasoline engine, and includes a supercharger 54. The turbocharger 54 is provided in the intake / exhaust system of the engine 10, and is a known exhaust turbine supercharger, that is, a turbo, which is rotationally driven by part or all of the exhaust of the engine 10 to boost the intake air of the engine 10. It is a charger. Specifically, as shown in FIG. 1, the supercharger 54 is provided in an exhaust pipe 56 of the engine 10 and is driven to rotate by exhaust of the engine 10, and in an intake pipe 60 of the engine 10. An intake compressor wheel 62 that is provided and rotated by the exhaust turbine wheel 58 to compress the intake air of the engine 10, and a rotary shaft 64 that connects the exhaust turbine wheel 58 and the intake compressor wheel 62 are provided. The engine 10 operates in a supercharged state that is supercharged by the supercharger 54 when sufficient exhaust of the engine 10 to drive the supercharger 54 is directed to the exhaust turbine wheel 58. On the other hand, if the exhaust of the engine 10 guided to the exhaust turbine wheel 58 is insufficient for driving the supercharger 54, the supercharger 54 is hardly driven, and the engine 10 is in excess of the supercharged state. The engine operates in a natural intake state (also referred to as an NA state or a non-supercharged state) in which the supply is suppressed, that is, a state of intake air that is not supercharged equivalent to a naturally aspirated engine without the supercharger 54.

  The engine 10 includes an intercooler 65 that cools the intake air supercharged by the supercharger 54. The intercooler 65 is disposed between the intake compressor wheel 62 and the electronic throttle valve 72 in the intake path constituted by the intake pipe 60 of the engine 10. Therefore, the intake air discharged from the intake compressor wheel 62 flows to the electronic throttle valve 72 via the intercooler 65.

  An exhaust bypass path 66 disposed in parallel with the exhaust path in which the exhaust turbine wheel 58 in the exhaust pipe 56 is provided, and a waste gate valve 68 for opening and closing the exhaust bypass path 66 are provided. The waste gate valve 68 can continuously adjust the opening θwg of the waste gate valve 68 (hereinafter referred to as waste gate valve opening θwg), and the electronic control unit 52 controls the electric actuator 70. Thus, the waste gate valve 68 is continuously opened and closed using the pressure in the intake pipe 60. Further, as the waste gate valve opening θwg is larger, the exhaust of the engine 10 becomes easier to be discharged through the exhaust bypass path 66, so that the engine 10 can be brought into the supercharging state from the exhaust port of the engine 10 to the extent that the exhaust can be made. Is obtained, the supercharging pressure Pcm (= PLin) by the supercharger 54 that is the outlet pressure of the intake compressor wheel 62 in the intake pipe 60, that is, the outlet pressure of the intake compressor wheel 62, is The larger the waste gate valve opening θwg, the lower the value. That is, the waste gate valve 68 adjusts the supercharging pressure Pcm by adjusting the amount of exhaust that drives the supercharger 54, specifically, the amount of exhaust supplied to the exhaust turbine wheel 58 of the supercharger 54. It functions as a supercharging pressure adjusting device to adjust. For example, a supercharging region that is an operating range (range of engine operating points) for setting the engine 10 in the supercharging state, and a low engine torque side with respect to the supercharging region and the engine 10 in the non-supercharging state A supercharging operation map divided into a non-supercharging region which is an operation range to be set is experimentally set in advance. When the electronic control device 52 shifts the operating point (engine operating point) of the engine 10 represented by the engine rotational speed Ne and the engine torque Te from the non-supercharging region to the supercharging region, for example, The supercharger 54 is supercharged by operating the waste gate valve 68 in the closing direction. Conversely, when the engine operating point is shifted from the supercharging region to the non-supercharging region, the supercharging by the supercharger 54 is stopped or suppressed by operating the waste gate valve 68 in the opening direction. The supercharging operation map is experimentally set in advance so that, for example, as large a driving force Fc as possible can be obtained in accordance with a driver's request, and fuel consumption deterioration of the vehicle 6 can be suppressed as much as possible. Has been. The driving force Fc is a propulsive force that propels the vehicle 6 in the traveling direction.

  In addition, when the engine 10 is in the supercharged state, the electronic control unit 52 is based on the vehicle state represented by the accelerator pedal opening PAP, the vehicle speed V, and the like, based on a relationship determined experimentally in advance. A target supercharging pressure Pcmtgt, which is a target value of the supercharging pressure Pcm, is sequentially determined, and the supercharger 54 is operated so that the supercharging pressure Pcm approaches the predetermined target supercharging pressure Pcmtgt. Specifically, the supercharging pressure Pcm is brought close to the target supercharging pressure Pcmtgt by controlling the waste gate valve opening θwg or the throttle opening θth. For example, the target boost pressure Pcmtgt is set to be larger as the accelerator pedal opening degree PAP is larger in accordance with the relationship determined experimentally in advance. That is, when the engine 10 is in the supercharging state, the electronic control unit 52 decreases the supercharging pressure Pcm by operating the waste gate valve 68, for example, as the accelerator pedal opening PAP is smaller.

  Further, the engine 10 includes an electronic throttle valve 72. The electronic throttle valve 72 is a valve mechanism that adjusts the intake air amount Qin of the engine 10 and is opened and closed by an electric throttle actuator 94. Specifically, the intake air amount Qin of the engine 10 decreases as the throttle opening degree θth that is the opening degree of the electronic throttle valve 72 is smaller, in other words, as the electronic throttle valve 72 is closed (squeezed). Further, the electronic throttle valve 72 is disposed downstream of the supercharger 54 in the intake path constituted by the intake pipe 60 of the engine 10. Specifically, the turbocharger 54 is disposed downstream of the intake compressor wheel 62.

  FIG. 3 is a diagram illustrating a signal input to the electronic control device 52 including a function as a control device of the vehicle drive device 7, that is, a vehicle drive control device, and a control function provided in the electronic control device 52. It is a functional block diagram for demonstrating the principal part of. The electronic control unit 52 includes a so-called microcomputer, and executes vehicle control related to, for example, the engine 10 and the automatic transmission 12 by performing signal processing according to a program stored in advance.

  The electronic control unit 52 includes a signal indicating the opening degree θth of the electronic throttle valve 72 detected by the throttle opening degree sensor 74, that is, the throttle opening degree θth, from each sensor and switch as shown in FIG. A signal indicating the upstream side pressure PHin of the intake compressor wheel 62 in the intake pipe 60 detected by 76, a signal of the intake compressor wheel 62 in the intake pipe 60 detected by a second intake sensor (supercharging pressure sensor) 78. A signal representing the downstream side pressure PLin (= supercharging pressure Pcm), a signal representing the waste gate valve opening degree θwg detected by the waste gate valve opening degree sensor 82, and an engine speed Ne detected by the engine speed sensor 84. A signal indicating the rotation speed Nout of the output gear 28 detected by the output rotation speed sensor 86, A signal from the accelerator pedal opening sensor 90 representing the accelerator pedal opening PAP that is the depression amount of the accelerator pedal 88 corresponding to the output demand, the rotational speed Nt of the turbine impeller 14b (hereinafter referred to as "turbine rotational speed Nt"), that is, A signal from the turbine rotation speed sensor 92 representing the rotation speed Nin (= Nt) of the transmission input shaft 26, a signal representing the vehicle speed V detected by the vehicle speed sensor 96, and the engine 10 detected by the intake air amount sensor 98. A signal representing the intake air amount Qin (hereinafter referred to as engine intake air amount Qin) is supplied. Since the rotational speed Nout of the output gear 28 corresponds to the vehicle speed V, the output rotational speed sensor 86 and the vehicle speed sensor 96 may be a common sensor. Further, since the compressor upstream side pressure PHin is the same as the atmospheric pressure Pair, the first intake sensor 76 also functions as an atmospheric pressure sensor for detecting the atmospheric pressure Pair. Further, the accelerator pedal opening PAP corresponds to the accelerator opening in the present invention.

  In addition, various output signals are supplied from the electronic control device 52 to each device provided in the vehicle 6. For example, the electronic control unit 52 is experimentally set in advance so that the driving force Fc in accordance with the driver's intention is obtained based on the accelerator pedal opening PAP and the engine rotational speed Ne detected sequentially. A target engine torque Tet that is a target value of the engine torque Te is sequentially determined. Then, the throttle opening θth and the ignition timing of the engine 10 are controlled so that the engine torque Te becomes the target engine torque Tet. For example, the electronic control unit 52 increases the throttle opening θth as the accelerator pedal opening PAP increases.

  By the way, when the accelerator pedal opening PAP is suddenly decreased from the state where the driver depresses the accelerator pedal 88 during vehicle acceleration, the driver may be oriented to driving that emphasizes acceleration performance. It is considered that the accelerator pedal 88 is highly likely to be depressed immediately after the rapid decrease in the accelerator pedal opening PAP. Under such circumstances, if the waste gate valve opening θwg is increased and the boost pressure Pcm is lowered as the accelerator pedal opening PAP decreases rapidly, the engine is temporarily driven due to a delay in supercharging during re-acceleration. There is a risk of causing the driver to feel inadequate. Therefore, the electronic control unit 52 controls the supercharging pressure Pcm so that the supercharging pressure Pcm is adequately secured in preparation for re-acceleration that may occur after the accelerator pedal opening degree PAP suddenly decreases. The main part of the control function will be described with reference to FIG.

  As shown in FIG. 3, the electronic control unit 52 includes an accelerator return amount calculation unit 100 that is an accelerator return amount calculation unit, a first accelerator return amount determination unit 102 that is a first accelerator return amount determination unit, and a second accelerator. The second accelerator return amount determination means 104, which is a return amount determination section, the supercharging pressure decrease suppression control means 106, which is a supercharging pressure decrease suppression control section, and the upshift prohibition means 108, which is an upshift prohibition section, are functionally provided. In preparation.

  The accelerator return amount calculation means 100 sequentially detects the accelerator pedal opening degree PAP by the accelerator pedal opening degree sensor 90, and the accelerator return amount is a decrease amount dPAP of the accelerator pedal opening degree PAP within a predetermined time TIME01. Calculate dPAP. For example, the accelerator return amount dPAP is calculated every predetermined time TIME01. The predetermined time TIME01 is experimentally set in advance, for example, in a very short time so that the accelerator return amount dPAP can indicate the agility indicating how quickly the driver performs the accelerator operation. In the accelerator return amount dPAP, the direction in which the accelerator pedal opening degree PAP decreases is the positive direction. Further, since the accelerator return amount dPAP is the accelerator return amount per predetermined time TIME01, it corresponds to an accelerator return speed (unit:% / sec) for decreasing the accelerator pedal opening degree PAP.

  The first accelerator return amount determination means 102 determines whether or not the accelerator return amount dPAP calculated by the accelerator return amount calculation means 100 is larger than a predetermined first determination value dPAP1x.

  The second accelerator return amount determination means 104 determines whether or not the accelerator return amount dPAP calculated by the accelerator return amount calculation means 100 is larger than a predetermined second determination value dPAP2x. The first determination value dPAP1x and the second determination value dPAP2x are both positive values, and it is determined that the accelerator return amount dPAP is larger than the first determination value dPAP1x or the second determination value dPAP2x. The second determination value dPAP2x is larger than the first determination value dPAP1x so that it is estimated that it is highly likely that the accelerator pedal 88 will be depressed immediately after the accelerator pedal opening PAP decreases. The value is set (dPAP2x> dPAP1x). Therefore, if the accelerator return amount dPAP is larger than the first determination value dPAP1x and further larger than the second determination value dPAP2x, the accelerator pedal 88 is more likely to be depressed immediately after the accelerator pedal opening PAP is decreased. It is estimated that.

  When the accelerator pedal opening degree PAP is decreased from the state where the accelerator pedal 88 is depressed, the supercharging pressure decrease suppression control means 106 decreases the supercharging pressure Pcm as the accelerator return amount dPAP increases (unit: The supercharging pressure lowering suppression control is performed to reduce (kPa / sec). Specifically, the supercharging pressure reduction suppression control changes the supercharging pressure Pcm decrease rate ΔPcm (hereinafter referred to as supercharging pressure decrease rate ΔPcm) stepwise with the first determination value dPAP1x as a threshold value. Further, in the supercharging pressure reduction suppression control, reducing the supercharging pressure reduction rate ΔPcm specifically means that the supercharging pressure Pcm is reduced by reducing the opening speed of the waste gate valve 68. This is to increase the time constant in the control to approach the target boost pressure Pcmtgt. Therefore, whether or not the supercharging pressure reduction rate ΔPcm is made small in the supercharging pressure reduction suppression control is compared under the condition that the supercharging pressure differences at which the supercharging pressure Pcm decreases are equal. That is, in the supercharging pressure decrease suppression control, the supercharging pressure decrease suppression control means 106 decreases the supercharging pressure decrease rate ΔPcm as the accelerator return amount dPAP increases. Is greater than the first determination value dPAP1x, the boost pressure when the boost pressure Pcm is reduced by a predetermined boost pressure difference as compared with the case where the accelerator return amount dPAP is equal to or less than the first determination value dPAP1x. The decrease rate ΔPcm is reduced. In other words, when the accelerator return amount dPAP is larger than the first determination value dPAP1x, the difference in the boost pressure at which the boost pressure Pcm decreases is equal to the case where the accelerator return amount dPAP is equal to or less than the first determination value dPAP1x. In comparison, the supercharging pressure reduction rate ΔPcm is made smaller. Whether or not the accelerator return amount dPAP is larger than the first determination value dPAP1x is based on the determination of the first accelerator return amount determination means 102. Further, the supercharging pressure decrease rate ΔPcm when the accelerator return amount dPAP is larger than the first determination value dPAP1x can avoid, for example, the occurrence of surging and the lack of the supercharging pressure Pcm during reacceleration. It is experimentally determined in advance.

  The upshift prohibiting unit 108 prohibits the upshift of the automatic transmission 12 when the second accelerator return amount determination unit 104 determines that the accelerator return amount dPAP is larger than the second determination value dPAP2x. Specifically, the upshift prohibiting unit 108 may completely prohibit the upshift of the automatic transmission 12 when the accelerator return amount dPAP is larger than the second determination value dPAP2x. The upshift is partially prohibited based on the accelerator return amount dPAP. That is, when the upshift prohibiting means 108 prohibits the upshift, it is based on the accelerator return amount dPAP from the upper limit gear map which is a relationship determined experimentally using the accelerator return amount dPAP as a parameter. The upper limit gear of the automatic transmission 12 is determined. If the current gear stage of the automatic transmission 12 is the same as the upper limit gear stage or a gear stage on the higher vehicle speed side than the upper limit gear stage, the upshift is prohibited. On the other hand, if the current gear is a lower gear than the upper gear, an upshift to the upper gear is allowed. Even if the current gear stage is a gear stage on the higher vehicle speed side than the upper limit gear stage, the downshift is not performed. Further, the upper limit gear stage map is tested in advance so that a good acceleration response can be obtained when the accelerator pedal 88 is re-depressed and the fuel consumption deterioration due to the high rotation of the engine 10 is suppressed. Is stipulated. Further, according to the upper limit gear stage map, the upper limit gear stage is set to a lower vehicle speed side gear stage as the accelerator return amount dPAP is larger.

  FIG. 4 is a flowchart for explaining the main part of the control operation of the electronic control unit 52, that is, the control operation when the accelerator pedal 88 that has been depressed during the acceleration of the vehicle is returned. It is repeatedly executed with an extremely short cycle time of about 10 msec. The control operation shown in FIG. 4 is executed alone or in parallel with other control operations.

  First, in step (hereinafter, “step” is omitted) SA1, an accelerator return amount dPAP within the predetermined time TIME01, that is, an accelerator return amount dPAP per predetermined time TIME01 is calculated. After SA1, the process proceeds to SA2. SA1 corresponds to the accelerator return amount calculation means 100.

  In SA2 corresponding to the first accelerator return amount determination means 102, it is determined whether or not the accelerator return amount dPAP calculated in SA1 is larger than the first determination value dPAP1x. If the determination of SA2 is affirmative, that is, if the accelerator return amount dPAP is larger than the first determination value dPAP1x, the process proceeds to SA3. On the other hand, if the determination of SA2 is negative, this flowchart ends.

  In SA3 corresponding to the supercharging pressure reduction suppression control means 106, the supercharging pressure reduction suppression control is executed. That is, compared to the case where the accelerator return amount dPAP is equal to or less than the first determination value dPAP1x, the supercharging pressure decrease rate ΔPcm when decreasing the supercharging pressure Pcm by a predetermined supercharging pressure difference is reduced. Specifically, the opening speed of the waste gate valve 68 is reduced, and thereby the time constant in the control for reducing the supercharging pressure Pcm is increased. For example, if the waste gate valve 68 is operated by duty control, in the supercharging pressure reduction suppression control, the waste gate valve 68 may be operated in the opening direction by setting a target value for the duty ratio. After SA3, the process proceeds to SA4.

  In SA4 corresponding to the second accelerator return amount determination means 104, it is determined whether or not the accelerator return amount dPAP calculated in SA1 is larger than the second determination value dPAP2x. When the determination of SA4 is affirmed, that is, when the accelerator return amount dPAP is larger than the second determination value dPAP2x, the process proceeds to SA5. On the other hand, if the determination of SA4 is negative, this flowchart ends.

  In SA5 corresponding to the upshift prohibiting means 108, the upshift of the automatic transmission 12 is prohibited. For example, the upshift of the automatic transmission 12 is prohibited according to the upper limit gear stage map.

  As described above, according to the present embodiment, when the engine 10 is in the supercharged state, the electronic control unit 52 supercharges as the accelerator pedal opening PAP is smaller, for example, by the operation of the waste gate valve 68. Reduce pressure Pcm. Then, the supercharging pressure decrease suppression control means 106 included in the electronic control unit 52 reduces the supercharging pressure decrease rate ΔPcm as the accelerator return amount dPAP (accelerator return speed) within the predetermined time TIME01 increases. The pressure drop suppression control is executed. Here, as the decrease of the accelerator pedal opening PAP is more rapid, the driver is more likely to drive with an emphasis on acceleration performance, and the driver performs an acceleration operation such as depressing the accelerator pedal 88 again. The possibility is considered high. Therefore, it is easy to obtain a sufficient supercharging pressure Pcm at the time of reacceleration after the accelerator pedal opening PAP is reduced, and there is an advantage that it is easy to satisfy the driver's acceleration request at the time of reacceleration.

  Further, according to this embodiment, in the supercharging pressure decrease suppression control, the supercharging pressure decrease suppression control means 106 decreases the supercharging pressure decrease rate ΔPcm as the accelerator return amount dPAP increases. When the return pressure dPAP is larger than the first determination value dPAP1x, the boost pressure Pcm is decreased by a predetermined boost pressure difference compared to the case where the accelerator return amount dPAP is equal to or less than the first determination value dPAP1x. Is to reduce the supercharging pressure decrease rate ΔPcm. Therefore, by comparing the accelerator return amount dPAP with the first determination value dPAP1x, it is possible to easily determine whether or not to decrease the supercharging pressure decrease rate ΔPcm.

  Further, according to the present embodiment, the upshift prohibiting means 108 performs the automatic shifting when the second accelerator return amount determination means 104 determines that the accelerator return amount dPAP is larger than the second determination value dPAP2x. The upshift of the machine 12 is prohibited. Accordingly, since it is possible to prevent downshifting at the time of reacceleration after the accelerator pedal opening PAP is decreased, the automatic transmission 12 is frequently shifted as the accelerator pedal opening PAP is temporarily increased or decreased. It is possible to avoid it.

  In addition, according to the present embodiment, the second determination value dPAP2x is set to a value larger than the first determination value dPAP1x (dPAP2x> dPAP1x). For this reason, reducing the supercharging pressure reduction rate ΔPcm in the supercharging pressure reduction suppression control is prioritized over the prohibition of the upshift. Therefore, there is a disadvantage that may occur due to the prohibition of the upshift, for example, the engine 10. It is easy to ensure acceleration responsiveness at the time of reacceleration while suppressing an increase in vibration and fuel consumption deterioration due to higher rotation of the engine.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this is an embodiment to the last, and this invention is implemented in the aspect which added various change and improvement based on the knowledge of those skilled in the art. Can do.

  For example, in the above-described embodiment, the vehicle 6 does not include an electric motor as a driving force source for traveling, but may be a hybrid vehicle including an electric motor for traveling.

  In the above-described embodiment, the flowchart of FIG. 4 includes SA4 and SA5. However, the SA4 and SA5 are not provided, and may be configured by SA1 to SA3.

  In the above-described embodiment, the automatic transmission 12 is a stepped transmission. However, the automatic transmission 12 may be a continuously variable transmission (CVT) such as a belt type, and the vehicle 6 includes the automatic transmission 12. You can leave it.

  In the above-described embodiment, the waste gate valve 68 functions as the supercharging pressure adjusting device that adjusts the supercharging pressure Pcm, but a mechanism or device other than the waste gate valve 68 functions as the supercharging pressure adjusting device. It doesn't matter.

  Further, in the above-described embodiment, the supercharging pressure reduction suppression control means 106 uses the first determination value dPAP1x as a threshold value for the accelerator return amount dPAP in the supercharging pressure reduction suppression control stepwise. Although the decrease rate ΔPcm is changed, without setting such a threshold value, for example, according to a map or the like in which the relationship between the accelerator return amount dPAP and the supercharging pressure decrease rate ΔPcm is experimentally determined in advance, the accelerator return amount dPAP is changed. On the other hand, the supercharging pressure reduction rate ΔPcm may be continuously changed.

  In the above-described embodiment, the vehicle 6 includes the torque converter 14 as shown in FIG. 1, but the torque converter 14 is not essential.

6: Vehicle 10: Engine 12: Automatic transmission 38: Drive wheel 52: Electronic control device (vehicle drive control device)
54: Supercharger 68: Wastegate valve (supercharging pressure adjusting device)

Claims (3)

A vehicle having an engine having a supercharger and a supercharging pressure adjusting device for adjusting a supercharging pressure by the supercharger, wherein the supercharging pressure is lowered by the supercharging pressure adjusting device as the accelerator opening is smaller Drive control device for
The vehicular drive control device characterized in that the lowering of the boost pressure is made smaller as the accelerator return speed for reducing the accelerator opening is larger. The higher the accelerator return speed, the smaller the decrease rate of the supercharging pressure means that the accelerator return speed is less than or equal to the first determination value when the accelerator return speed is greater than a predetermined first determination value. 2. The vehicle drive control device according to claim 1, wherein a reduction speed of the supercharging pressure when the supercharging pressure is reduced by a predetermined supercharging pressure difference is reduced as compared with a certain case. The vehicle includes an automatic transmission that outputs power of the engine to drive wheels,
The upshift of the automatic transmission is prohibited when the accelerator return speed is larger than a predetermined second determination value that is larger than the first determination value. Vehicle drive control device.

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